Stitching head apparatus

ABSTRACT

A wire stitching head is disclosed for successively producing a series of uniformly shaped and sized stitches from a continuous length of wire and includes a reciprocating stitch forming bar and a relatively shiftable stitch driving bar operated by a rotating cam wheel provided with an arcuate feeding cam which coacts with a guide roller to feed a predetermined length of wire into stitch forming position upon each rotation of the cam wheel. The stitch forming bar and stitch driving bar are guided in their reciprocating paths of motion by a guide member having a channelway into which the preselected length of wire is positioned for the forming and driving operation. The preselected length of wire, determined by the arcuate length of the aforementioned feeding cam, is just slightly less than the width of the channelway in the guide member whereby such length of wire does not reach the opposite wall in the channelway at any time during the stitch forming or stich driving operation thereby avoiding deflection and bending of the wire which otherwise occurs especially at high speed operation. To more precisely regulate the length of wire fed into stitch forming position, the aforementioned guide roller is mounted on the frame of the apparatus for rotation with the cam wheel and preferably by being geared thereto. Also to aid in positioning the wire in the stitch forming apparatus, a novel wire check structure, comprising a pair of unidirectional clutches between which the wire passes, is mounted immediately adjacent the aforementioned guide member to minimize the distance between the wire check and a passageway in the guide member through which the wire passes to reach the stitch forming position. Additionally, wire guide means are provided which include a hollow tube, a portion thereof being disposed in a curvilinear path which is opposite the direction of the bias established by the supply of wire. In this manner, the natural bias of the wire in the direction of the coil rolls from which it was stored is reversed and the wire is straightened out prior to being fed to the stitch forming portion of the apparatus. Finally, after a stitching cycle has been completed, the deenergization of the driving mechanism of the stitching head apparatus is arranged to take place when the moving parts thereof approach a condition of zero momentum thereby substantially reducing the stresses which must be withstood by such elements as the clutch-brake utilized to halt the motion of the apparatus.

United States Patent [191 Barland STITCHING HEAD APPARATUS [75]Inventor: Lauri C. Barland, West Chester, Pa.

Related US. Application Data [631 Continuation-impart of Ser. No.37,190, May 14,

1970, Pat. No. 3,642,187.

[52] US. Cl. 227/90 [51] Int. Cl. B27! 7/02 [58] Field of Search 227/82,83, 84, 85,

[56] I References Cited UNITED STATES PATENTS 5/1951 Zeruneith 227/846/1939 Robinson. 227/82 1,246,455 11/1917 Niskanen. 227/91 2,226,91612/1940 Zeruneith 227/89 3,173,592 3/1965, l-lerbst 227/7 PrimaryExaminer-Granville Y. Custer, Jr. Attorney-Lawrence l. Lerner et al.

[57] ABSTRACT A wire stitching head is disclosed for successivelyproducing a series of uniformly shaped and sized stitches from acontinuous length of wire and includes a reciprocating stitch formingbar and a relatively shiftable stitch driving bar operated by a rotatingcam wheel provided with an arcuate feeding cam which coacts with a guideroller to feed a predetermined length of wire into stitch formingposition upon each rotation of the cam wheel. The stitch forming bar andstitch driving bar are guided in'their reciprocating paths of motion bya guide July 24, 1973 member having'a channelway into which thepreselected length of wire is positioned for the forming and drivingoperation. The preselected length of wire, determined by the arcuatelength of the aforementioned feeding cam, is just slightly less than thewidth of the channelway in the guide member whereby such length of wiredoes not reach the opposite wall in the channelway at any time duringthe stitch forming or stich driving operation thereby avoidingdeflection and bending of the wire which otherwise occurs especially athigh speed operation. To more precisely regulate the length of wire fedinto stitch forming position, the aforementioned guide roller is mountedon the frame of the apparatus for rotation with the cam wheel andpreferably by'being geared thereto. Also to aid in positioning the wirein the stitch forming apparatus, a novel wire check structure,comprising a pair of unidirectional clutchesbetween which the wirepasses, is mounted immediately adjacent the aforementioned guide memberto minimize the distance between the wire check and a passageway in theguide member through which the wire passes to reach the stitch formingposition. Additionally, wire guide means are provided which include ahollow tube, a portion thereof being disposed in a curvilinear pathwhich is opposite the direction of the bias established by the supply ofwire. In this manner, the natural bias of the wire in the direction ofthe coil rolls from which it was stored is reversed and the wire isstraightened out prior to being fed to the stitch forming portion of theapparatus; Finally, after a stitching cycle has been completed, thedeenergization of the driving mechanism of the stitching head apparatusis arranged to take place when the moving parts thereof approach acondition of zero momentum thereby substantially reducing the stresseswhich must be withstood by such elements as the clutch-brake utilized tohalt the motion of the apparatus.

'8 Claims, 3 Drawing Figures 1 July 24, 1973 PAIENIEDJuLzmn SHEET 1 0F 3uvvzxvron LAURI c. BARLAND LERNER, DAVID 8 LITTENBERG A TTORNEYS CLUTCH-M BRAKE PATENTEDJULZWB 3.747. 825

STITCHING HEAD APPARATUS CROSS REFERENCES TO RELATED APPLICATIONS Thisapplication is a continuation-in-part of U.S. Pat. application Ser. No.37,190 filed May 14, 1970 in the name of Lauri C. Barland and entitledStitching Head Apparatus, now U.S. Pat. 3,642,187, assigned to theassignee of the instant application.

FIELD OF THE INVENTION This invention relates to wire stitching heads,more particularly wire stitching heads capable of successively producinga series of uniformed shaped and sized stitches from a continuous lengthof wire, and more particularly to such a wire stitching head havingsignificant improvements which make possible wire stitching at extremelyhigh rates of speed.

BACKGROUND OF THE INVENTION In U.S. Pat. application Ser. No. 37,190filed May 14, l970 in the name of Lauri C. Barland, and assigned to theassignee of the instant invention, there is disclosed a wire stitchinghead of the type to which the instant invention is directed. Thus thestitching head of the aforementioned Harland application includes, asthe heart of its mechanism, a motor driven earn wheel which performs anumber of functions which may be briefly summarized as follows.

First, the cam wheel carries along its periphery an arcuate feeding camwhich, together with a cooperating guide roller, functions tointermittently feed preselected lengths of wire into the stitch formingposition upon each revolution of the cam wheel. Secondly the cam wheelpivotally carries on a forward surface thereof a pair of links one ofwhich is pivotally connected to a reciprocating stitch forming bar andthe other of which is pivotally connected to a stitch driving bar whichfunctions to drive a stitch into the work piece after the stitch hasbeen formed by the aforementioned stitch forming bar. The stitch formingbar and stitch drivingbar are guided in their reciprocating paths oftravel by a guide member having a channelway into which each preselectedlength of wire is successively fed prior to being formed and driven intothe work piece positioned therebeneath. This basic machine, although nowenjoying wide spread popularity in the industry, has been found toencounter certain difficulties when the speed of operation thereof issubstantially increased.

For example, at extremely high rates of stitching speed, for example1500 stitches per minute, the stitches being produced by the stitchinghead tend to become non-uniformly shaped, leading sometimes to improperstitch placement or even worse, sometimes to ajamming ofthe stitchinghead. Also, at extremely high rates of stitching speed, the momentum ofthe moving parts becomes extremely high and attempts to deactivate thestitching head, for example by applying a braking force to the rotatingcam wheel to which the stitch forming bar and stitch driving bar areattached, sometimes applies such stresses that the braking mechanismcompletely fails (i.e., is physically destroyed). Moreover, at highrates of stitching speed, such problems as controlling the feeding ofthe wire and preventing back-slip during the interval between feeds,becomes especially acute creating unacceptable deviations in the form,shape and placement of the stitches produced by the stitching headapparatus.

SUMMARY OF THE INVENTION The instant invention is directed to a wirestitching head of the general arrangement discussed above, but isprovided with significant improvements which have simply, inexpensively,and effectively eliminated the aforementioned problems associated withoperating the wire stitching head at increased rates of speed.

Specifically, applicant has discovered that one of the reasons the wirestitches become deformed or otherwise improperly shaped, is because whena length of wire is fed into the channelway of the aforementioned guidemember at an extremely high rate of speed, it must absorb aproportionally greater amount of energy from the shock it receives whenits leading end bangs into the far wall of the channelway. Of course,the energy it absorbs is dissipated by the undesirable bending anddeflection of the wire mentioned previously. In the instant invention,this problem is completely eliminated by providing that the preselectedlength of wire being fed into the aforementioned guide member forsubsequent forming and driving is less than the width of the channelwaysuch that the leading end of the wire never quite reaches the far wallof the channelway when it is fed into stitch forming and drivingposition. As will be described in greater detail, such result isaccomplished by preselectively selecting the arcuate length of theaforementioned feeding cam to correspond to the preselected length ofwire which is just less than the width of the aforementioned channelway.In addition, and in a manner to be further described, controlledaccuracy is assured by providing a direct power drive for theaforementioned guide roller and by providing a novel wire check,comprising a pair of unidirectional clutches which prevents wireslippage back toward the supply roll in between periods of wire feed.Also, novel wire straightening means are provided adjacent the wirecheck such that the length of wire finally fed into the aforementionedchannelway will be transversely oriented with respect to the directionof travel of the formet and driving bars and not curved in the directionof its storage position on a supply roll.

With respect to the problem of clutch-brake failure at high speeds, theinstant invention includes a system for deactivating the driving meansassociated with the aforementioned multifunction cam wheel at a point intime when the stitch forming means and stitch driving means areapproaching a condition of zero momentum (at the point where thereciprocating forming and driving bars reverse their direction oftravel). In this manner, the braking mechanism has virtually no-momentumto absorb regardless of the speed at which the stitching head isoperating.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 1 FIG. 1 is afront elevational view of the stitching head of the present inventionwith the front cover plate thereof removed to show the operative partsof the mechanism;

FIG. 2 is a side elevational view of the stitching head of the presentinvention; and

FIG. 3 is a schematic representation of the certain aspects of theinstant invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTIONTurning to the Figures, wherein like numerals are employed to designatelike elements, it will be observed from FIGS. 1 and 2 that the wirestitching head of the present invention is in the form of a compactmotor driven organization which is adapted to be suitably mounted at theupper end of a main support frame (not shown), which is provided with ahorizontally disposed work supporting surface 12 fitted with a clenchingmember 14 for clenching the wire stitches as the same are successivelyformed in the stitching head and driven thereby through the work W to bestitched.

As mentioned previously, the instant invention represents improvementsto the stitching head of the aforementioned Barland application Ser. No.37,190, and as such includes: top and bottom channel guide members 28,30 secured on the front surface 18 of a frame 16 for guiding areciprocating stitch forming bar 32 which has a bifurcated lower end 34,a driving bar 36 mounted for reciprocal motion within guideways 38provided on the confronting inner surface 39 of the bifurcated lower end34 of the forming bar 32; a multi-function cam wheel 40 rigidly securedto one end 42 of a driven shaft 44 suitably journalled by ball bearings46 and 48 in the front and rear surfaces 18 and of the frame 16; anelectric motor 50 the output shaft 52 of which is selectivelyconnectable to the driven shaft 44 by a clutch mechanism 54; and apivoting anvil 56 the nose portion 58 of which is utilized in the stitchforming operation in a manner more fully set forth in the aforementionedBarland application, the contents of which are hereby incorporatedherein by specific reference thereto.

In order to understand the manner in which the improvements of theinstant invention function in a wire stitching machine of the type setforth in the Barland application, it is perhaps worthwhile to begin adescription of the instant invention by providing a short description ofthe overall operation of a stitching head of the type described in saidBarland application Ser. No. 37,190.

Initially it should be pointed out that the cam wheel 40 carries anarcuate feeding cam 60 which projects slightly into the path of travel62 defined by the periphery of the cam wheel 40 and a guide roller 64the specific construction of which is set out in great detail in theaforementioned Barland application. Thus for each revolution of the camwheel 40 (affected when the clutch 54 interconnects the continuouslyrotating output shaft 52 of the motor 50 with the driven shaft 44), apreselected length of wire, corresponding to the arcuate length of thefeeding cam 60 will be advanced from a supply reel (not shown) throughtubular wire guides 68, 70, through a wire check 71 forming a part ofthe instant invention, and a passageway 72 provided in the lower guidemember 30, into channelway 74 provided in the lower guide member 30.

It will be appreciated that the clearance between the guide roller 64and the periphery of the cam wheel 40 is such that the wire 66 fitsfreely therebetween under normal circumstances. It is only when theprojecting feed cam 60 enters the path of travel 62 that the wire is"sandwiched and thereby advanced. Of course, during intervals ofnon-feed, when the wire 66 is free with respect to the feedingmechanism, the wire check 71 to be described in greater detail, preventsthe wire from being pulled back toward its supply roll, not shown. Also,it will be appreciated that the arcuate or peripheral length of thefeeding cam 60 is preselectively choosen to correspond to the overalllength of the ultimately desired stitch. Yet to be described inconnection with an improvement of the instant invention is the manner inwhich the preselected length of wire corresponding to the arcuate lengthof the feed cam 60, is chosen with respect to the width of thechannelway 74 in the lower guide member 30.

Provided on the rearward side of the cam wheel 40 (as viewed in FIG. 1)is a second cam surface 76 which, as best seen in FIG. 2, cooperateswith a following rod 78 to maintain the pivotally mounted anvil 56 inthe wire supporting position illustrated in FIG. 2. It will beappreciated, that when the cam 76 rotates free of the following rod 78,a spring biased plunger 80 will rotate the anvil 56 in a clockwisedirection as viewed in FIG. 2 and out of the path of travel of thedriver bar 36 as will be described below. It should be pointed out, thatthe placement of the cams 60 and 76 relative to one another, and thearcuate length of the cam 76, are chosen such that the anvil 56 and itswire supporting nose 58, will be in the proper wire supporting positionillustrated in FIG. 2, as the wire 66 is being advanced into thechannelway 74 in the manner previously described.

Finally, the front surface 82 of the cam wheel 40 carries an outstandingpin 84 to which is pivotally connected to one end of a pair of links 86,88 respectively. The opposite end of the link 86 is pivotally connectedto the pin outstanding from the forming bar 32, and the opposite end ofthe link 88 is pivotally connected to pin 92 provided on the driver bar36. It will be noted that the pin 90 joining the link 86 to the formerbar 32 is mounted off center and to the right (as viewed in FIG. 1) withrespect to the location of the pin 92 which joins the link 88 to thedriving bar 36. This mounting is intentionally chosen, such that thelength of the reciprocating stroke of the driver bar 36 is greater thanthe length of the reciprocating stroke of the bifurcated forming bar 32which together function in the following manner.

Assuming that the feeding cam 60 has positioned the next length of wirein the channelway 74 (appropriately supported by the anvil 56 by virtueof the cam surface 76 and the follower rod 78), continued rotation ofthe cam wheel 40 causes the links 86 and 88 to begin the downwardstrokes of the former bar 32 and the driver bar 36 respectively. Becausethe lower end of the former bar 32 is initially lower than the bottomedge 94 of the driver bar 36, the wedge like surfaces 96 of thebifurcated end 34 of the former bar 32 quickly engage the opposite endsof the wire length positioned in the channel 74 and bend them downwardaround the anvil nose 58 to form the desired U shaped stitch illustratedat 98 in FIG. 2. Immediately thereafter, the lower end 94 of the drivingbar 36 reaches the bight portion of the U shaped stitch and continues todrive the stitch (within the confines of the confronting faces 39 of thebifurcated forming bar) through the work piece W and into engagementwith the clenching member 14. It should be pointed out that the wire isinitially cut from the continuous supply running through the passageway72 by the side edge 100 of the bifurcated forming bar 32. Additionally,it should be pointed out that the positioning and length of the secondcam 76 provided on the cam wheel 40 is such that just as the driving bar36 engages the bight portion of the U shaped stitch, the cam 76 leavesthe following rod 78 and the spring biased plunger 80 quickly rotatesthe anvil 56 out of the path of travel of the driving bar 36.

Thus the stitch is fed, formed, driven, and clenched in one quickcontinuous operation, all motions of which are generated by the singlemulti-function cam wheel 40. During the second half cycle of cam wheelrotation, the motions are reversed with the driving bar 36 being liftedbefore the forming bar 32.

With respect to FIG. 3, the actual initiation of a stitching cyclebegins when anappropriate photoelectric sensing means 97 functions tosense the leading edge of the work piece 14 as it advances past thestitching head 10. When the photocell detects the presence of theleading edge, it energizes a conventional timer 99 which is set to timeout upon the expiration of a predetermined amount of time correspondingto the length of the front flaps of the carton to be constructed fromthe box blank 14 being stitched by the machine. When the timer 99 istimed out, it generates a signal applied to the gate 101 of asemiconductor controlled rectifier 103 which is thereby turned on tocomplete a circuit comprising voltage source 106, clutch coil 148 (FIG.2), the SCR 103, and to ground. Once clutch coil 148 is energized, thenin a manner described in further detail in the aforementioned Barlandapplication, the clutch 54 is activated to interconnect the outputof themotor 50 with the cam wheel 40. It is to be understood, however, thatany suitable clutch or clutch brake combination may be used in theinstant invention and not just the clutch brake described in detail inthe aforementioned Barland application.

To control the deactivation of the stitching operation, sensing contacts105 are positioned in the path of travel of the reciprocating stitchformer bar 32. A counter 107 responsive to the pulses produced by thecontacts 105 is utilized to preset the number of stitches desired. Whenthe preset number of stitches have been sensed by contacts 105 andaccumulated by counter 107; a signal is applied on the line 109 whichthe capacitor-resistive network 111 converts to a pulse appearing on theline 113 which is applied to the base 115 of a transistor 117 whichturns on to thereby momentarily make a low impedance bypass circuitaround the SCR 103 which is thereby extinguished. Thus coil 148 isdeenergized, the clutch 54 is braked, and the stitching head ceasesoperation.

Turning to the specific contributions of the instant invention, it waspreviously mentioned that at extremely high rates of speed, there is atendency for the leading end 119 of the wire to bang against the farwall 121 of the passageway 74 thereby bending and deforming the wire andthe subsequent stitch formed thereby. To avoid this problem, the arcuatelength A of the feeding cam 60 of the cam wheel 40, corresponding to thelength of wire which will be fed into the channelway 74, ispreselectively chosen to be slightly less than the width of thechannelway 74 designated B in FIG. 3. In this manner, the end 119 of thewire never reaches the far wall 121 and the aforementioned problem iscompletely eliminated.

Since the preselected length of wire fed into the channelway 74 isanimportant factor in eliminating the tendency of the wire to bang againstthe far wall thereof, it will be appreciated that the wire feedingoperations described previously must be especially accurate. To thisend, and to avoid any possibility of slippage during the feedingoperation, the instant invention provides that the guide roller 64 bepositively driven for rotation with the cam wheel 40 during the feedingoperation. Specifically and as seen perhaps most clearly in FIG. 2, theguide roller 64 (the details of which are disclosed and claimed in theaforementioned Barland application), is fixedly mounted by a key way 123to the reduced diameter end 125 of a shaft 127. The shaft 127 isprovided with a gear 129 the teeth 131 of which mesh with gear teeth 133provided around the periphery of the cam wheel 40. In this manner, theguide roller 64 is driven synchronously with the cam wheel 40 therebymaterially increasing the control and accuracy of the feeding operation.

At the other end of the feeding operation, the novel wire check means 71is provided to prevent backup of the wire 66 toward its supply (notshown) during the intervals between positive wire feed. Beforedescribing the wire check 71 in detail, it is to be appreciated, andconsidered one of the improvements of the instant invention, that thewire check 71 is secured to the frame 16 immediately adjacent the lowerguide member to thereby minimize the distance between the wire check andthe passageway 72 through which the wire passes on its way to thechannelway 74.

In accordance with one aspect of the invention, the wire check 71includes a pair of shafts 135, 137 supported between end plates 139 and141 respectively. Mounted on each shaft is a roller 143, 145 spacedapart from one another to define a feed path for wire passingtherethrough. Each of the rollers is rotatable in only one direction,that corresponding to the direction of feed of the wire toward thestitch forming channelway 74. To accomplish such unidirectionalrotation, the rollers may comprise for example the type ofunidirectional clutches manufactured by the Torrington Company ofTorrington, Connecticut but of course, any other suitable unidirectionalroller arrangement may be provided to establish the direction ofrotation desired.

To facilitate the insertion of the wire during an initial loadingoperation, the shaft 137 may be rotated in a counterclockwise directionabout pivot 147. A spring 149 wrapped around the pivot 147 and havingone end connected to the arm upon which the shaft 137 is mounted and theother end connected to a fixed pin 151 normally biases the roller 145toward the roller 143.

To further help in properly aligning the length of wire within thechannelway 74, it is desirable that the length of wire in the channelwayremain in a position transverse with respect to the reciprocating pathof travel of the forming bar 32 and the driving bar 36. To this end, thewire guiding tube terminates in a portion 153 which is disposed in acurvilinear path which is opposite to the direction of bias establishedon the supply of wire by virtue of its storage on a roll (not shown).Thus by the time the wire emerges from the passageway 72 in the lowerguide member 30 it has been straightened out and no longer attempts toreturn to the direction of curvature in which it was stored on thesupply roll.

Finally, as was mentioned previously, when operating at extremely highrates of stitching speed, it sometimes happens that the clutch mechanismsuch as S4 physically fails in its attempt to apply a braking action tothe moving parts of the stitching head which of course gatherincreasingly high momentum with higher operating speeds. To eliminatethis problem, the instant invention provides that the sensing contacts105 are positioned in the reciprocating path of motion of the formingbar 32 adjacent the uppermost point of travel designated 155 in FIG. 3of the forming bars 32. Of course it will be appreciated that the point155 represents the point of reversal of travel of the reciprocatingforming bar 32, such that this point 155 corresponds to a condition ofzero momentum for the reciprocating parts. Therefore, and in accordancewith this aspect of the instant invention, location of the contacts 105adjacent the point of zero momentum, guarantees that the clutch 54 willbe subjected to a minimum, virtually zero, momentum when it applies abraking force to the moving parts of the stitching head. Thus,regardless of what speeds are attained, the clutch 54 never sees" thehigh momentums involved when it applies the braking force and theaforementioned failure thereof is completely eliminated. Preferably, thecontacts 105 are spaced from the uppermost point of travel 155 by adistance designated C in FIG. 3 corresponding to the time required forthe circuitry to deenergize the coil 148 (and the mechanism responsivethereto, described in the aforementioned Barland application, toactually disengage the clutch and apply the braking action) whereby thestitch forming means and stitch driving means will just reach their zeromomentum position when the brake is actually applied to the shaft 44.

Although this invention has been described with re spect to itspreferred embodiments, it should be understood that many variations andmodifications will now be obvious to those skilled in the art, and it ispreferred, therefore, that the scope of the invention be limited, not bythe specific disclosure herein, only by the appended claims.

I claim: 1. A wire stitching head comprising; a frame; stitch formingmeans mounted on said frame for forming a preselectively shaped stitchfrom a preselected length of wire which has been supplied thereto;stitch driving means movably mounted with respect to said stitch formingmeans for driving the stitch formed by said stitch forming means into awork piece positioned in predetermined relationship with respect to saidstitching head; and wire feeding means for intermittently supplying saidpreselected length of wire to said stitch forming means from a supply ofsaid wire; said wire feeding means including;

a cam wheel mounted on said frame, driving means for selectivelyrotating said cam wheel,

a guide roller mounted on said frame, said guide roller mounted on saidframe in proximity to said cam wheel to define a path of travel for saidsupply of wire therebetween,

said cam wheel having an arcuate feeding cam of said preselected length,said arcuate feeding cam projecting into said path of travel each timesaid cam wheel is rotated a revolution by said driving means; andfurther including linking means connected between said cam wheel andsaid stitch forming means and said stitch driving means for operatingsaid stitch forming means and said stitch driving means in reciprocatingpaths of motion in response to rotation of said cam wheel by saiddriving means; and further including start means for initiating theenergization of said driving means; and

stop means for deenergizing said driving means; said stop meansincluding sensing means for deenergizing said driving means when saidstitch forming means and said stitch driving means approach a conditionof zero momentum.

2. The wire stitching head of claim 1 wherein said sensing meansincludes switching means positioned ih said reciprocating path of motionadjacent the uppermost point of travel of said stitch forming means.

3. The wire stitching head of claim 2 wherein said switching means isspaced from said uppermost point of travel of said stitch forming meansby a distance corresponding to the time required for said stop means todeenergize said driving means; whereby said stitch forming means andstitch driving means will just reach their zero momentum position whensaid driving means is deactivated.

4. A wire stitching head comprising:

a frame,

stitch forming means mounted on said frame for forming a preselectivelyshaped stitch from a prese lected length of wire which has been suppliedthereto;

stitch driving means movably mounted with respect to said stitch formingmeans for driving the stitch formed by said stitch forming means into awork piece positioned in predetermined relationship with respect to saidstitching head,

wire feeding means for intermittently supplying said preselected lengthof wire to said stitch forming means from a supply of said wire;

driving means for operating at least said stitch forming means and saidstitch driving means; and further including start means for initiatingthe energization of said driving means;

stop means for deenergizing said driving means;

said stop means including sensing means for deenergizing said drivingmeans when said stitch forming means and said stitch driving meansapproach a condition of zero momentum.

5. The wire stitching head of claim 4 wherein sai stitch forming meansand said stitch driving means move with respect to said frame inreciprocating paths of motion; and

wherein said sensing means includes switching means positioned in saidreciprocating path of motion adjacent the uppermost point of travel ofsaid stitch forming means.

6. The wire stitching head of claim 5 wherein said switching means isspaced from said uppermost point of travel of said stitch forming meansby a distance corresponding to the time required for said stop means todeenergize said driving means; whereby said stitch forming means andstitch driving means will just reach their zero momentum position whensaid driving means is deactivated.

7. The wire stitching head of claim 4 and further including a guidemember secured to said frame for guiding the movement of said stitchforming means, said guide member including a channelway into which saidpreselected length of wire is fed by said wire feeding means and withinwhich said stitch forming means rehaving an arcuate feeding cam of saidpreselected length projecting into said path of travel each time saidcam wheel is rotated a revolution by said driving means; and

wherein the arcuate length of said feeding cam corresponds to saidpreselected length of wire.

I II

1. A wire stitching head comprising; a frame; stitch forming meansmounted on said frame for forming a preselectively shaped stitch from apreselected length of wire which has been supplied thereto; stitchdriving means movably mounted with respect to said stitch forming meansfor driving the stitch formed by said stitch forming means into a workpiece positioned in predetermined relationship with respect to saidstitching head; and wire feeding means for intermittently supplying saidpreselected length of wire to said stitch forming means from a supply ofsaid wire; said wire feeding means including; a cam wheel mounted onsaid frame, driving means for selectively rotating said cam wheel, aguide roller mounted on said frame, said guide roller mounted on saidframe in proximity to said cam wheel to define a path of travel for saidsupply of wire therebetween, said cam wheel having an arcuate feedingcam of said preselected length, said arcuate feeding cam projecting intosaid path of travel each time said cam wheel is rotated a revolution bysaid driving means; and further including linking means connectedbetween said cam wheel and said stitch forming means and said stitchdriving means for operating said stitch forming means and said stitchdriving means in reciprocating paths of motion in response to rotationof said cam wheel by said driving means; and further including startmeans for initiating the energization of said driving means; and stopmeans for deenergizing said driving means; said stop means includingsensing means for deenergizing said driving means when said stitchforming means and said stitch driving means approach a condition of zeromomentum.
 2. The wire stitching head of claim 1 wherein said sensingmeans includes switching means positioned in said reciprocating path ofmotion adjacent the uppermost point of travel of said stitch formingmeans.
 3. The wire stitching head of claim 2 wherein said switchingmeans is spaced from said uppermost point of travel of said stitchforming means by a distance corresponding to the time required for saidstop means to deenergize said driving means; whereby said stitch formingmeans and stitch driving means will just reach their zero momentumposition when said driving means is deactivated.
 4. A wire stitchinghead comprising: a frame, stitch Forming means mounted on said frame forforming a preselectively shaped stitch from a preselected length of wirewhich has been supplied thereto; stitch driving means movably mountedwith respect to said stitch forming means for driving the stitch formedby said stitch forming means into a work piece positioned inpredetermined relationship with respect to said stitching head, wirefeeding means for intermittently supplying said preselected length ofwire to said stitch forming means from a supply of said wire; drivingmeans for operating at least said stitch forming means and said stitchdriving means; and further including start means for initiating theenergization of said driving means; stop means for deenergizing saiddriving means; said stop means including sensing means for deenergizingsaid driving means when said stitch forming means and said stitchdriving means approach a condition of zero momentum.
 5. The wirestitching head of claim 4 wherein said stitch forming means and saidstitch driving means move with respect to said frame in reciprocatingpaths of motion; and wherein said sensing means includes switching meanspositioned in said reciprocating path of motion adjacent the uppermostpoint of travel of said stitch forming means.
 6. The wire stitching headof claim 5 wherein said switching means is spaced from said uppermostpoint of travel of said stitch forming means by a distance correspondingto the time required for said stop means to deenergize said drivingmeans; whereby said stitch forming means and stitch driving means willjust reach their zero momentum position when said driving means isdeactivated.
 7. The wire stitching head of claim 4 and further includinga guide member secured to said frame for guiding the movement of saidstitch forming means, said guide member including a channelway intowhich said preselected length of wire is fed by said wire feeding meansand within which said stitch forming means reciprocates; saidpreselected length of wire being less than the width of said channelway.8. The wire stitching head of claim 7 wherein said wire feeding meansincludes a cam wheel mounted on said frame, said driving means rotatingsaid cam wheel upon activation thereof; a guide roller mounted on saidframe in proximity to said cam wheel to define a path of travel for saidwire therebetween; said cam wheel having an arcuate feeding cam of saidpreselected length projecting into said path of travel each time saidcam wheel is rotated a revolution by said driving means; and wherein thearcuate length of said feeding cam corresponds to said preselectedlength of wire.